Core C will provide a state of the art proteomics core to improve the understanding of the molecular changes in the mitochondria associated with reactive oxygen species (ROS) and aging. The four research projects seek to understand the role of mitochondrial catalase and mimetics on health and lifespan in mouse models. Integral to the success of the program project grant is the measurement of changes in relative mitochondrial protein abundance and half-life in health, disease, and aging. To support the needs of the individual research projects, the Proteomics Core has three specific aims: 1)to perform perform the unbiased detection of differences in peptide/protein abundance between complex mixtures. To understand the effect of ROS on mitochondrial function we will provide the capability to comprehensively detect differences in A) protein abundance between mitochondrial enriched fractions and B) peptide abundance between samples following enrichment of peptides with oxidative modifications. 2) to perform targeted analysis of protein abundance for mitochondrial proteins of interest. 3) to perform global measurement of individual mitochondrial protein halflife. An active area of technology development within the core will be refining the capability for the measurement of individual protein half-life in a rodent system. We have the capability to measure mitochondrial protein half-life for hundreds of proteins in a single measurement.